The present invention relates to cameras.
In particular, the present invention relates to cameras which are capable of automatically determining the exposure of film therein.
In particular, the present invention relates to that type of camera which is capable of receiving light internally to be measured with the light brightness being memorized prior to opening of the shutter.
Thus, as is well known, with many single lens reflex cameras the light travels along the optical axis of the objective to be reflected by a mirror in the camera up to the viewfinder where the light is measured while the operator can simultaneously view the object which is to be photographed, and of course at this time the mirror prevents the light from reaching the film plane. In order to make an exposure it is necessary to tilt the mirror away from the optical axis so that the light can continue to travel along the optical axis past the location of the mirror to the film plane, and in this way upon opening of the shutter the film will be exposed. As a result of the requirements of this type of structure it is necessary to memorize in some way the brightness of the light at the object which is to be photographed so that this one of the factors which controls exposure of film can be utilized during exposure.
It is widely known to use a memory capacitor for such purposes. With such memory capacitor devices, however, it is difficult to provide a circuit which will apply the capacitor-memorized information to a switching circuit for control of the shutter, and errors frequently occur.